Sex-related survival differences in murine cardiomyopathy are associated with differences in TNF-receptor expression
J. Clin. Invest. Toshiaki Kadokami, et al. 106:589 doi:10.1172/JCI9307 [Go to this article.]

Figure 2
Echocardiographic studies in TNF1.6 mice. (a–h) Representative images of M-mode echocardiogram of TNF1.6 mice (a–d) and wild-type littermates (e–h). Male TNF1.6 mice exhibited a markedly dilated left ventricle with reduced fractional shortening (a) and poor responsiveness to isoproterenol (b). Female TNF1.6 mice showed hypertrophied but not dilated left ventricle (c) with relatively preserved isoproterenol responsiveness (d). Both male and female wild-type mice had good left ventricular systolic function and showed a significant increase in fractional shortening after isoproterenol challenge (e–h). (i) Left ventricular fractional shortening before (filled bars) and after (open bars) isoproterenol injection in TNF1.6 and wild-type mice. Wild-type mice of both sexes showed preserved systolic function at baseline measurement, and fractional shortening was significantly increased up to 40% after isoproterenol challenge. By contrast, male TNF1.6 mice exhibited decreased fractional shortening at baseline and completely lost the responsiveness to β-adrenergic stimulation. Basal left ventricular contraction was preserved in female TNF1.6 mice, whereas the increase in fractional shortening after isoproterenol injection was significant but impaired. Values are mean ± SD. TG, TNF1.6 mice; WT, wild-type mice; M, male; F, female; FS, fractional shortening; NS, not significant. ^AP < 0.05 vs. WT; ^BP < 0.01; ^CP = 0.001. (j) Correlation of left ventricular mass estimated from echocardiographic measurements and gravimetric mass determination. A total of 16 TNF1.6 or wild-type mice were sacrificed immediately after echocardiographic examination, hearts were excised, and left ventricles were trimmed and weighed. Left ventricular mass was calculated using the formula in the text. Left ventricular mass determined by the two different methods showed an excellent correlation (P < 0.001).